Tractor

ABSTRACT

A tractor includes: a vehicle body; an engine bonnet forming an engine compartment; an engine; a first exhaust-gas cleaning device that purifies an exhaust gas and is above the engine such that its long side is substantially parallel to a vehicle-body lateral width direction; a second exhaust-gas cleaning device that purifies the exhaust gas and is behind the engine such that its long side is substantially parallel to the lateral width direction; a vehicle body frame; and a supporting tool that is supported by the vehicle body frame, supports the first and second exhaust-gas cleaning devices, and includes a support column that extends upward from the vehicle body frame along a front portion of the second exhaust-gas cleaning device, and a support arm that extends forward from an upper portion of the support column along a lower portion of the first exhaust-gas cleaning device.

BACKGROUND Technical Field

The present invention relates to a tractor.

Description of Related Art

As shown in patent literature 1 and 2, for example, the tractor isequipped with an engine bonnet (bonnet) that forms an enginecompartment, and in the engine compartment, an exhaust-gas cleaningdevice (exhaust-gas cleaning process device) is installed above theengine.

PRIOR ART LITERATURE

[Patent Literature 1] JP 2013-112284 A

[Patent Literature 2] JP 2015-143508 A

There is a demand for a tractor to be provided with a plurality ofexhaust-gas cleaning devices for cleaning exhaust gas discharged from anengine. Examples of the plurality of exhaust-gas cleaning devicesinclude an exhaust-gas cleaning device that cleans exhaust gas using acleaning filter and an exhaust-gas cleaning device that cleans exhaustgas using a reducing agent.

When the conventional art is adopted and the first exhaust-gas cleaningdevice and the second exhaust-gas cleaning device are installed in theengine compartment, the first exhaust-gas cleaning device and the secondexhaust-gas cleaning device are located above the engine, and thus, evenwhen the size of one of the first exhaust-gas cleaning device and thesecond exhaust-gas cleaning device is smaller than the size of the otherexhaust-gas cleaning device, the mounting height of the engine bonnetmust be set to correspond to the larger exhaust-gas cleaning device.Therefore, the mounting height of the engine bonnet is increased.

SUMMARY

One or more embodiments of the present invention provide a tractor forwhich it is possible to provide a first exhaust-gas cleaning device anda second exhaust-gas cleaning device in an engine compartment whilekeeping the mounting height of the engine bonnet low, keeping thefront-back length of the engine compartment short, and supporting thefirst exhaust-gas cleaning device and the second exhaust-gas cleaningdevice onto the vehicle body frame while in an appropriate connectionstate.

The tractor of one or more embodiments of the present invention isprovided with: a vehicle body; an engine bonnet forming an enginecompartment; an engine that is disposed in the engine compartment; afirst exhaust-gas cleaning device and a second exhaust-gas cleaningdevice provided in the engine compartment for purifying exhaust gasdischarged from the engine; and a support member (i.e., a supportingtool) supported by the vehicle body frame and supporting the firstexhaust-gas cleaning device and the second exhaust-gas cleaning deviceis provided, the first exhaust-gas cleaning device being provided abovethe engine and having a long side substantially parallel to avehicle-body lateral width direction (or a vehicle-body horizontaldirection), and the second exhaust-gas cleaning being provided behindthe engine and having a long side substantially parallel to thevehicle-body lateral width direction; wherein, the supporting member isprovided with a support column extending upward from the vehicle bodyframe along the front portion of the second exhaust-gas cleaning devicewhile supporting the front portion and a support arm extending forwardfrom the upper portion of the support column along a lower portion ofthe first exhaust-gas cleaning device while supporting the lowerportion.

According to this configuration, the first exhaust-gas cleaning device,which is the smaller of the first exhaust-gas cleaning device and thesecond exhaust-gas cleaning device, is installed above the engine, andthe larger second exhaust-gas cleaning device is installed behind theengine, and the mounting height of the engine bonnet can be set based onthe size of the small first exhaust-gas cleaning device. Furthermore,since the long sides of both the first and second exhaust-gas cleaningdevices are substantially parallel to the vehicle-body lateral widthdirection, the first and second exhaust-gas cleaning devices can beaccommodated compared to the case where the long sides are substantiallyparallel to the vehicle-body longitudinal direction, and it is possibleto shorten the length of the space in a vehicle-body longitudinaldirection (or a vehicle-body front-back direction) necessary for theinstallation of the first exhaust-gas cleaning device, while keeping themounting height of the engine bonnet low and the longitudinal length ofthe engine compartment shorter, and a second exhaust-gas cleaning devicecan be provided in the engine compartment.

Because the positional relationship between the first exhaust-gascleaning device and the second exhaust-gas cleaning device is supportedby the vehicle body frame in a state where the positional relationshipis set by the support member, the first exhaust-gas cleaning device andthe second exhaust-gas cleaning device can be easily connected; forexample, even in a connection structure that does not have a functionenabling adjustment of the positional relationship between the firstexhaust-gas cleaning device and the second exhaust-gas cleaning device,the first exhaust- gas cleaning device and the second exhaust-gascleaning device can be connected in a positional relationshipadvantageous for connection.

In one or more embodiments of the present invention, the vehicle bodyframe is provided with a flywheel housing extending backward from theback portion of the engine and positioned below the second exhaust-gascleaning device, and the support column extends upward from the flywheelhousing toward the vehicle body.

According to this configuration, since the support column extends upwardfrom the flywheel housing located below the second exhaust-gas cleaningdevice, the length of the support column can be shortened, and it ispossible to firmly support the first exhaust-gas cleaning device and thesecond exhaust-gas cleaning device onto the vehicle body frame such thatthe first exhaust-gas cleaning device and the second exhaust-gascleaning device do not readily swing.

The tractor of one or more embodiments of the present invention isprovided with a position adjustment tool that can adjust a supportposition of the second exhaust-gas cleaning device on the support columnin a vehicle-body vertical direction (or a vehicle-body up-downdirection), the vehicle-body longitudinal direction, and thevehicle-body lateral width direction.

According to the present configuration, even when there is a positionalshift between the first exhaust-gas cleaning device and the secondexhaust-gas cleaning device in the vehicle-body vertical direction, thevehicle-body longitudinal direction, and the vehicle-body lateral widthdirection due to manufacturing errors in the support member, by forexample, adjusting the positional shift via the position adjustmenttool, for example, the first exhaust-gas cleaning device and the secondexhaust-gas cleaning device can be connected even in a connectionstructure not provided with a function for correcting the positionalshift, and thus the connection structure can be simplified in that aspecial positional shift adjustment portion is not required in aconnection structure that connects the first exhaust-gas cleaning deviceand the second exhaust-gas cleaning device.

The tractor of one or more embodiments of the present invention isprovided with a lower support portion that is supported below thesupport column and supports a lower portion of the second exhaust-gascleaning device.

According to this configuration, the front portion of the secondexhaust-gas cleaning device is supported by the support column, and thelower portion of the second exhaust-gas cleaning device is supported bythe support column, and thus the second exhaust-gas cleaning device canbe firmly supported by the support member.

The tractor of one or more embodiments of the present invention isprovided with a second position adjustment tool that can adjust asupport position of the second exhaust-gas cleaning device on the lowersupport portion in the vehicle-body vertical direction, the vehicle-bodylongitudinal direction, and the vehicle-body lateral width direction.

According to the present configuration, even when there is a positionalshift between the first exhaust-gas cleaning device and the secondexhaust-gas cleaning device in the vehicle-body vertical direction, thevehicle-body longitudinal direction, and the vehicle-body lateral widthdirection due to manufacturing errors in the support member, forexample, by adjusting the positional shift via a second positionadjustment tool, for example, the first exhaust-gas cleaning device andthe second exhaust-gas cleaning device can be connected even in aconnection structure not provided with a function for correcting thepositional shift, and thus the connection structure can be simplified inthat a special positional shift adjustment portion is not required in aconnection structure that connects the first exhaust-gas cleaning deviceand the second exhaust-gas cleaning device.

In one or more embodiments of the present invention, the lower portionof the support column comprises a washer portion that is connected tothe vehicle body frame to make the support column supported by thevehicle body frame, and the lower support portion constitutes a part ofthe washer portion.

According to this configuration, the washer portion serves as aconnection member for supporting the lower support portion on thesupport column, and thus the structure of providing the lower supportportion on the support post portion can be simplified without requiringa special connection member.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a left side view illustrating an entirety of a tractor.

FIG. 2 is a left side view illustrating a first exhaust-gas cleaningdevice and a second exhaust-gas cleaning device.

FIG. 3 is a plan view illustrating the first exhaust-gas cleaning deviceand the second exhaust-gas cleaning device.

FIG. 4 is a back view illustrating a support member.

FIG. 5 is a perspective view of the support member in an exploded state.

FIG. 6 is a right side view illustrating left and right brake operationdevices.

FIG. 7 is an explanatory diagram illustrating a summary of assembly ofthe brake pedal.

FIG. 8 is a back view illustrating a steering-post cover and a panelcover.

FIG. 9 is a back view of a panel cover provided with another example ofone or more embodiments.

FIG. 10 is a perspective view of a steering-post cover provided withanother example of one or more embodiments.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention are described below based on thedrawings.

Note that in the following description, in regards to a travelingvehicle body of a tractor, the direction of arrow F illustrated in FIG.1 is defined as “vehicle-body front”, the direction of arrow B isdefined as “vehicle-body back”, the direction of arrow U is defined as“vehicle-body up”, the direction of arrow D is defined as “vehicle-bodydown”, the direction heading toward the surface of the page is definedas “vehicle-body left”, and the direction heading toward the reverseface of the page is defined as “vehicle-body right”.

[Overall Configuration of Tractor]

As illustrated in FIG. 1 , the tractor is provided with a travelingvehicle body 3 supported by a pair of left and right front wheels 1,which can be steered and driven, and a pair of left and right backwheels 2, which can be driven. A vehicle body frame 4 of the travelingvehicle body 3 is constituted by an engine 5, a flywheel housing 6connected to a back portion of the engine 5, a clutch housing 7connected to a back portion of the flywheel housing 6, a transmissioncase 7 a connected to a back portion of the clutch housing 7, and afront frame 8 connected to a lower portion of the engine 5. A motor unit9 provided with the engine 5 is formed in a front portion of thetraveling vehicle body 3. A driver's seat 10 and a driving unit 12,which is provided with a steering wheel 11 whereby a steering operationof the front wheels 1 is performed, are formed in a back portion of thetraveling vehicle body 3. A linking mechanism 13, which connects a workapparatus such as a rotary tilling apparatus (not illustrated) in amanner enabling a raising and lowering operation of the work apparatus,and a power takeoff shaft 14, which takes power from the engine 5 andoutputs this to the connected work apparatus, are provided in a backportion of the transmission case 7 a. Reference numeral 20 illustratedin FIG. 1 is a ROPS frame.

[Configuration of Motor Unit]

As illustrated in FIGS. 1 and 2 , the motor unit 9 is provided with anengine compartment 15. The engine compartment 15 is formed by an enginebonnet 16, which covers the engine compartment 15 from above and thefront; a partition member 17 that forms a partition between the enginecompartment 15 and the driving unit 12; and the like.

As illustrated in FIGS. 1 and 2 , the engine 5, a radiator 18 that coolsthe engine 5, and a first exhaust-gas cleaning device (DPF) 21 andsecond exhaust-gas cleaning device (SCR) 22 that perform cleaningprocesses of exhaust gas exhausted by the engine 5 are provided in theengine compartment 15.

[Configuration of Radiator]

As illustrated in FIG. 1 , the radiator 18 is provided in front of theengine 5. A blowing action of a rotary fan 19 positioned between theradiator 18 and the engine 5 introduces cooling air from outside theengine compartment 15 to inside the engine compartment and supplies thecooling air to the radiator 18. The cooling air is supplied to theradiator 18 in a state of the cooling air passing through the radiator18 from front to back. In the radiator 18, engine cooling water iscooled by heat exchange between the supplied cooling air and the enginecooling water. The engine 5 is cooled by the cooled engine cooling waterbeing supplied to the engine 5.

[Configurations of First Exhaust-Gas Cleaning Device and SecondExhaust-Gas Cleaning Device]

The engine 5 is a diesel engine. As illustrated in FIGS. 2 and 3 , thefirst exhaust-gas cleaning device 21 is provided above the engine 5 in astate wherein a long side of the first exhaust-gas cleaning device issubstantially parallel to a vehicle-body lateral width direction. Amaximum length H in a vehicle-body vertical direction of the firstexhaust-gas cleaning device 21 is set to be shorter than a maximumlength W in a vehicle-body longitudinal direction of the firstexhaust-gas cleaning device 21. As illustrated in FIGS. 2 and 3 , anexhaust-gas suctioning portion 21 a, which is provided to a part on oneend side, in a vehicle-body lateral width direction, of the firstexhaust-gas cleaning device 21, and an exhaust-gas exhausting portion 5a, which is provided to the engine 5, are connected. An exhaust-gasdischarging portion 21 b is provided to a part on another end side, inthe vehicle-body lateral width direction, of the first exhaust-gascleaning device 21. In one or more embodiments, the exhaust-gassuctioning portion 21 a protrudes downward from a lower portion of thefirst exhaust-gas cleaning device 21 at an end portion on a vehicle-bodyleft horizontal side of the first exhaust-gas cleaning device 21, andthe exhaust-gas discharging portion 21 b protrudes backward from an endportion on a vehicle-body right horizontal side of the first exhaust-gascleaning device 21.

In the first exhaust-gas cleaning device 21, the exhaust gas exhaustedby the engine 5 from the exhaust-gas exhausting portion 5 a is suctionedby the exhaust-gas suctioning portion 21 a into the device, and dieselmicroparticles included in the suctioned exhaust gas are collected by acollection filter (not illustrated). This performs an exhaust-gascleaning process of decreasing the diesel microparticles. The exhaustgas subjected to the cleaning process is discharged from the exhaust-gasdischarging portion 21 b.

As illustrated in FIGS. 2 and 3 , the second exhaust-gas cleaning device22 is provided behind the engine 5 in a state wherein a long side of thesecond exhaust-gas cleaning device is substantially parallel to thevehicle-body lateral width direction. An exhaust-gas introductionportion 22 a, which is provided to a part on one end side, in thevehicle-body lateral width direction, of the second exhaust-gas cleaningdevice 22, and the exhaust-gas discharging portion 21 b of the firstexhaust-gas cleaning device 21 are connected by a connecting pipe 23. Anexhaust-gas discharging portion 22 b is provided to a part on anotherend side, in the vehicle-body lateral width direction, of the secondexhaust-gas cleaning device 22. In one or more embodiments, theexhaust-gas introduction portion 22 a is provided to an end portion on avehicle-body left horizontal side of the second exhaust-gas cleaningdevice 22, and the exhaust-gas discharging portion 22 b is provided toan end portion on a vehicle-body right horizontal side of the secondexhaust-gas cleaning device 22.

In the second exhaust-gas cleaning device 22, the exhaust gas dischargedby the first exhaust-gas cleaning device 21 from the exhaust-gasdischarging portion 21 b is supplied by the connecting pipe 23 to theexhaust-gas introduction portion 22 a and introduced by the exhaust-gasintroduction portion 22 a into the device, and the introduced exhaustgas is subjected to the cleaning process by a reducing agent.Specifically, aqueous urea as the reducing agent is injected into theintroduced exhaust gas, hydrolyzing the exhaust gas. This performs anexhaust-gas cleaning process of decreasing nitrogen oxides included inthe exhaust gas. The exhaust gas subjected to the cleaning process isexhausted from the exhaust-gas discharging portion 22 b to avehicle-body horizontal outer side.

As illustrated in FIG. 3 , the first exhaust-gas cleaning device 21 issupported in an attachment disposition wherein the part on the other endside, in the vehicle-body lateral width direction, is swung anddisplaced toward a vehicle-body front side with respect to the part onthe one end side, in the vehicle-body lateral width direction, in astate wherein the exhaust-gas suctioning portion 21 a is a swingingshaft. That is, the first exhaust-gas cleaning device 21 is supported ina disposition wherein in a plan view, the longitudinal direction thereofis inclined relative to the vehicle-body lateral width direction. Asillustrated in FIG. 2 , the exhaust-gas introduction portion 22 a of thesecond exhaust-gas cleaning device 22 extends diagonally backward andupward from the second exhaust-gas cleaning device 22. A positionalrelationship between the exhaust-gas discharging portion 21 b of thefirst exhaust-gas cleaning device 21 and the exhaust-gas introductionportion 22 a of the second exhaust-gas cleaning device 22 can be made tobe a positional relationship appropriate for adopting a connecting pipe23 having no bellows or other adjustment means of adjusting thepositional relationship between the exhaust-gas discharging portion 21 band the exhaust-gas introduction portion 22 a. This can be done bybringing the first exhaust-gas cleaning device 21 and the secondexhaust-gas cleaning device 22 in proximity to each other in thevehicle-body longitudinal direction and by directly connecting theexhaust-gas suctioning portion 21 a of the first exhaust-gas cleaningdevice 21 to the exhaust-gas exhausting portion 5 a of the engine 5.

As illustrated in FIGS. 2 and 3 , a back portion 21 c of the firstexhaust-gas cleaning device 21 is positioned on a vehicle-body back sideof a back end portion of the engine 5. In a plan view, the back portion21 c of the first exhaust-gas cleaning device 21 and the secondexhaust-gas cleaning device 22 overlap.

As illustrated in FIGS. 2 and 3 , the partition member 17 that forms thepartition between the engine compartment 15 and the driving unit 12 isprovided across a back location of the second exhaust-gas cleaningdevice 22 and a lower location of the second exhaust-gas cleaning device22. The partition member 17 is configured so a part 17 a—positioned inthe lower location of the second exhaust-gas cleaning device 22—of thepartition member 17 is positioned further toward a vehicle-body frontside than a part 17 b—positioned in the back location of the secondexhaust-gas cleaning device 22—of the partition member 17. The part 17a—positioned in the lower location of the second exhaust-gas cleaningdevice 22—of the partition member 17 is provided with a portion in aninclined state that, in moving toward its lower end side, is positionedmore to a vehicle-body front side. A footwell of the driving unit 12 canbe extended below the second exhaust-gas cleaning device 22.

As illustrated in FIG. 6 , electrical wires 24 are provided across theengine compartment 15 and the driving unit 12. In one or moreembodiments, a plurality of electrical wires 24 is provided. However, itis also possible for only one to be provided. The electrical wires 24enter from the engine compartment 15 into the footwell of the drivingunit 12 by passing below a part positioned in a central portion in thevehicle-body lateral width direction of the partition member 17. Theelectrical wires 24 transmit information relating to actuation of theengine 5 to gauges of the driving unit 12. A portion of the electricalwires 24 that is positioned on a driving-unit side of the partitionmember 17 is wired in a state of conforming to the part 17 a—positionedin the lower location of the second exhaust-gas cleaning device 22—ofthe partition member 17 in the footwell of the driving unit 12. Theelectrical wires 24 pass through a conduit 25. The conduit 25 issupported on the partition member 17 by a clamp 26.

[Support Member of Exhaust-Gas Cleaning Devices]

As illustrated in FIGS. 2, 3, and 4 , the first exhaust-gas cleaningdevice 21 and the second exhaust-gas cleaning device 22 are supported onthe vehicle body frame 4 via a support member (i.e., the supportingtool) 30. The first exhaust-gas cleaning device 21 and the secondexhaust-gas cleaning device 22 are supported by the vehicle body frame 4in a state wherein the positional relationship between the exhaust-gasdischarging portion 21 b of the first exhaust-gas cleaning device 21 andthe exhaust-gas introduction portion 22 a of the second exhaust-gascleaning device 22 is set by the support member 30.

As illustrated in FIGS. 2, 3, 4, and 5 , the support member 30 isprovided with a support column 31 that extends upward from the vehiclebody frame 4 in a state of conforming to a front portion 22 c of thesecond exhaust-gas cleaning device 22 and supports the front portion 22c of the second exhaust-gas cleaning device 22, a support arm 32 thatextends in a vehicle-body forward direction from an upper portion of thesupport column 31 in a state of conforming to a lower portion 21 d ofthe first exhaust-gas cleaning device 21 and supports the lower portion21 d of the first exhaust-gas cleaning device 21, and a lower supportportion 33 that is provided to a lower portion of the support column 31and supports a lower portion 22 d of the second exhaust-gas cleaningdevice 22.

As illustrated in FIGS. 2, 4, and 5 , the support column 31 has a washerportion 34 provided to the lower portion of the support column 31 and issupported on the vehicle body frame 4 by the washer portion 34 beingconnected to the vehicle body frame 4. The connection of the washerportion 34 to the vehicle body frame 4 is performed by the flywheelhousing 6 constituting the vehicle body frame 4. The flywheel housing 6is positioned below the second exhaust-gas cleaning device 22 and cankeep a length of the support column 31 short.

As illustrated in FIGS. 2, 4, and 5 , the support column 31 is providedwith left and right strut rods 31 a lined up at an interval in thevehicle-body lateral width direction. A lower strut-portion reinforcingrod 31 b, which connects lower portions of the strut rods 31 a, and anupper strut-portion reinforcing rod 31 c, which connects upper portionsof the strut rods 31 a, are provided across the left and right strutrods 31 a. The left and right strut rods 31 a are constituted by steelpipes.

As illustrated in FIGS. 2, 4, and 5 , a front support portion 31 dsupporting the second exhaust-gas cleaning device 22 is provided to eachof the left and right strut rods 31 a. The front portion 22 c of thesecond exhaust-gas cleaning device 22 is supported by the support column31 by front connecting portions 22 e—provided in two locations, left andright, in the front portion 22 c of the second exhaust-gas cleaningdevice 22—being connected to the front support portion 31 d.

As illustrated in FIGS. 2, 4, and 5 , washer plates 34 a provided torespective lower portions of the left and right strut rods 31 a areprovided to the washer portion 34. In the washer portion 34, the leftand right washer plates 34 a being connected to the flywheel housing 6by a plurality of connecting bolts provides a detachable connection tothe flywheel housing 6.

As illustrated in FIGS. 2, 4, and 5 , the lower support portion 33 isprovided with lower support pieces 33 a provided to the lower portionsof the left and right strut rods 31 a. The left and right lower supportpieces 33 a are provided to the strut rods 31 a by being formed on thewasher plates 34 a. The lower support portion 33 is provided to thewasher portion 34. The lower portion 22 d of the second exhaust-gascleaning device 22 is supported by the lower support portion 33 by lowerconnecting portions 22 f—provided in two locations, left and right, inthe lower portion 22 d of the second exhaust-gas cleaning device22—being connected to the lower support pieces 33 a.

As illustrated in FIGS. 2, 4, and 5 , the support arm 32 is providedwith arm bodies 32 a that extend in the vehicle-body forward directionfrom respective upper portions of the left and right strut rods 31 a. Anarm reinforcing rod 32 b connecting the left and right arm bodies 32 ais provided across distal end portions of the left and right arm bodies32 a. Among the left and right arm bodies 32 a, the left arm body 32 ais configured to connect via a relay member 32 c to a lower connectingportion 21 e provided to the lower portion 21 d of the first exhaust-gascleaning device 21. The right arm body 32 a is configured to connectdirectly to the lower connecting portion 21 e of the first exhaust-gascleaning device 21.

[Configuration of Position Adjustment of Exhaust-Gas Cleaning Devices]

As illustrated in FIGS. 2, 4, and 5 , the support member 30 is providedwith a position adjustment tool 35 that can adjust a support position—inthe vehicle-body vertical direction, the vehicle-body longitudinaldirection, and the vehicle-body lateral width direction—of the secondexhaust-gas cleaning device 22 on the support column 31 and with asecond position adjustment tool 37 that can adjust a support position—inthe vehicle-body vertical direction, the vehicle-body longitudinaldirection, and the vehicle-body lateral width direction—of the secondexhaust-gas cleaning device 22 on the lower support portion 33.

When there is a position shift between the exhaust-gas dischargingportion 21 b of the first exhaust-gas cleaning device 21 and theexhaust-gas introduction portion 22 a of the second exhaust-gas cleaningdevice 22, so the positional relationship between the exhaust-gasdischarging portion 21 b and the exhaust-gas introduction portion 22 abecomes appropriate and the exhaust-gas discharging portion 21 b and theexhaust-gas introduction portion 22 a can be appropriately connected bythe connecting pipe 23 having no position adjustment function, thepositional relationship between the exhaust-gas discharging portion 21 band the exhaust-gas introduction portion 22 a can be adjusted by theposition adjustment tool 35 and the second position adjustment tool 37.

Specifically, as illustrated in FIGS. 2, 4, and 5 , the positionadjustment tool 35 is provided with an adjustment member 36 positionedbetween the front connection portion 22 e of the second exhaust-gascleaning device 22 and the front support portion 31 d of the supportcolumn 31, a first connecting bolt 36 a connecting the front connectingportion 22 e and the adjustment member 36, and a second connecting bolt36 b connecting the front support portion 31 d and the adjustment member36.

As illustrated in FIGS. 2, 4, and 5 , the second position adjustmenttool 37 is provided with a second adjustment member 38 positionedbetween the lower connecting portion 22 f of the second exhaust-gascleaning device 22 and the lower support piece 33 a of the supportcolumn 31, a third connecting bolt 38 a connecting the lower connectingportion 22 f and the second adjustment member 38, and a fourthconnecting bolt 38 b connecting the lower support piece 33 a and thesecond adjustment member 38.

A hole diameter of a through hole (not illustrated) of the adjustmentmember 36 into which the first connecting bolt 36 a is inserted is madegreater than an outer diameter of the first connecting bolt 36 a for aconfiguration enabling position shifting of the front connecting portion22 e relative to the adjustment member 36. A through hole (notillustrated) of the position adjustment member 36 into which the secondconnecting bolt 36 b is inserted is made greater than an outer diameterof the second connecting bolt 36 b for a configuration enabling positionshifting of the adjustment member 36 relative to the front supportportion 31 d.

A hole diameter of a through hole (not illustrated) of the secondadjustment member 38 into which the third bolt 38 a is inserted is madegreater than an outer diameter of the third connecting bolt 38 a for aconfiguration enabling position shifting of the adjustment member 36relative to the front support portion 31 d. A hole diameter of a throughhole (not illustrated) of the second adjustment member 38 into which thefourth connecting bolt 38 b is inserted is made greater than an outerdiameter of the fourth connecting bolt 38 b for a configuration enablingposition shifting of the adjustment member 36 relative to the frontsupport portion 31 d.

In the position adjustment tool 35, among the first connecting bolt 36a, the second connecting bolt 36 b, the third connecting bolt 38 a, andthe fourth connecting bolt 38 b, tightening of a connecting boltcorresponding to desired position adjustment is loosened. Performing anoperation of moving the second exhaust-gas cleaning device 22 shifts theposition of the second exhaust-gas cleaning device 22 relative to thesupport member 30. This changes the support position—in the vehicle-bodyvertical direction, the vehicle-body longitudinal direction, and thevehicle-body lateral width direction—of the second exhaust-gas cleaningdevice 22 on the support column 31 in a manner corresponding to theoperation that is performed of moving the second exhaust-gas cleaningdevice 22.

In the second position adjustment tool 37, among the first connectingbolt 36 a, the second connecting bolt 36 b, the third connecting bolt 38a, and the fourth connecting bolt 38 b, tightening of a connecting boltcorresponding to desired position adjustment is loosened. Performing anoperation of moving the second exhaust-gas cleaning device 22 shifts theposition of the second exhaust-gas cleaning device 22 relative to thesupport member 30. This changes the support position—in the vehicle-bodyvertical direction, the vehicle-body longitudinal direction, and thevehicle-body lateral width direction—of the second exhaust-gas cleaningdevice 22 on the lower support portion 33 in a manner corresponding tothe operation that is performed of moving the second exhaust-gascleaning device 22.

[Configuration of Driving Unit]As illustrated in FIG. 1 , the drivingunit 12 is provided behind the engine compartment 15. As illustrated inFIGS. 1, 3, and 8 , the driving unit 12 is provided with the driver'sseat 10, the steering wheel 11 whereby the steering operation of thefront wheels 1 is performed, a left brake operation unit 40L wherebybrakes (not illustrated) for the left back wheel are operated, and aright brake operation unit 40R whereby brakes (not illustrated) for theright back wheel are operated.

[Configurations of Left Brake Operation Unit and Right Brake OperationUnit]

As illustrated in FIG. 8 , the left brake operation unit 40L and theright brake operation unit 40R are provided to the right and below thesteering wheel 11. As illustrated in FIGS. 3, 6, and 8 , the left brakeoperation unit 40L and the right brake operation unit 40R are eachprovided with a brake pedal 41, a return spring 42 that subjects thebrake pedal 41 to an operation of being returned to an initial position(“off”), and a master cylinder 43 connected to the brake pedal 41.

As illustrated in FIG. 6 , the brake pedal 41 is provided with a pedalarm 41 a and with a footboard 41 b provided at a lower end portion ofthe pedal arm 41 a. A support shaft 44 is provided at an upper portionof the pedal arm 41 a. The support shaft 44 is supported by a supportportion 45 provided to the traveling vehicle body 3. The brake pedal 41is supported on the traveling vehicle body 3 in a state of being able toswing between the initial position (“off”) and a braking position (“on”)by using a shaft core P of the support shaft 44 as a swinging fulcrum.The brake pedal 41 is positioned to the initial position (“off”) by thepedal arm 41 a abutting a stopper 47.

As illustrated in FIG. 6 , the partition member 17 forming the partitionbetween the engine compartment 15 and the driving unit 12 is disposedfurther toward a vehicle-body front side than the brake pedal 41. Thereturn spring 42 is engaged to the pedal arm 41 a and a spring supportportion 17 d provided to the partition member 17. The return spring 42biases the brake pedal 41 to swing to the initial position (“off”) byusing the partition member 17 as a counterforce member.

As illustrated in FIG. 6 , the partition member 17 is configured so thepart 17 a, which corresponds to the footboard 41 b, of the partitionmember 17 is positioned further toward a vehicle-body front side thanthe part 17 b, which corresponds to the support shaft 44, of thepartition member 17. A front portion of the footwell of the driving unit12 can be extended forward past the support shaft 44.

As illustrated in FIG. 6 , the master cylinder 43 is provided on avehicle-body back side of the support shaft 44 of the brake pedal 41.The master cylinder 43 is fixed in a detachable manner to the supportportion 45. A slidable operation shaft 43 a of the master cylinder 43and an operation arm 41 c provided to the brake pedal 41 areinterconnected. The operation arm 41 c extends from the pedal arm 41 atoward an opposite side of a side whereon the footboard 41 b ispositioned relative to the support shaft 44.

In both the left brake operation unit 40L and the right brake operationunit 40R, when the brake pedal 41 is subjected to a stepping operationagainst the return spring 42 and enters the braking position (“on”), theoperation shaft 43 a of the master cylinder 43 is subjected to a slidingoperation to a pushed-in side by the operation arm 41 c. The mastercylinder 43 supplies operational hydraulic pressure to the brakes (notillustrated), and the brakes perform an operation of switching to abraking state. When the stepping operation of the brake pedal 41 isreleased, the brake pedal 41 is subjected to an operation of returningto the initial position (“off”) by the return spring 42, and theoperation shaft 43 a of the master cylinder 43 is subjected to a slidingoperation to a pulled-out side by the operation arm 41 c. The impartingof the operational hydraulic pressure by the master cylinder 43 to thebrakes is released, and the brakes perform an operation of switching toan initial state.

[Configuration of Return Spring]

As illustrated in FIGS. 3 and 6 , the return spring 42 is constituted bya torsion coil spring and is provided with a coil portion 42 a, an arm42 b extending from one end side of the coil portion 42 a, and an arm 42c extending from another end side of the coil portion 42 a. The coilportion 42 a is fitted onto the support shaft 44, and the return spring42 is supported by the support shaft 44. The arm 42 b on the one endside is engaged to the spring support portion 17 d of the partitionmember 17. The arm 42 c on the other end side is engaged to the pedalarm 41 a.

As illustrated in FIG. 6 , a bent end portion 42 d engaged to the pedalarm 41 a is provided to the arm 42 c on the other end side. A throughhole 46 whereto the bent end portion 42 d is engaged is provided to thepedal arm 41 a. A shape of the through hole 46 is made to be a shapeinto which the bent end portion 42 d, which moves along the shaft core Pof the support shaft 44, can be inserted. The return spring 42 and thebrake pedal 41 can be assembled by the following assembly outline.

As illustrated in FIG. 7 , the coil portion 42 a fits the return spring42 onto the support shaft 44, and the arm 42 b on the one end side isplaced in a state of being engaged to the partition member 17. Thereturn spring 42 is in a free state. The stopper 47 is removed from thesupport portion 45. The brake pedal 41 is attached to the support shaft44 and swung up, and the brake pedal 41 is operated in a dispositionopposing the support shaft, wherein the footboard 41 b is positioned ina position higher than when the brake pedal 41 is positioned in theinitial position (“off”). The brake pedal 41 in this attitude ofopposing the support shaft is guided to the support shaft 44 and movedtoward the return spring 42. By moving the brake pedal 41, the bent endportion 42 d of the return spring 42 moves toward the pedal arm 41 a ina direction along the shaft core p of the support shaft 44, is insertedinto the through hole 46 from an inner side of the pedal arm 41 a, andmoves to an outer side of the pedal arm 41 a. Next, the brake pedal 41is swung down. At this time, the operation arm 41 c enters a slit 17 eprovided in the partition member 17. The stopper 47 is attached to thesupport portion 45, and the brake pedal 41 is moved to the initialposition (“off”). This causes the brake pedal 41 to be stopped by thestopper 47. As illustrated in FIG. 6 , the bent end portion 42 d engagesto the pedal arm 41 a, the return spring 42 is provided with an elasticrestoring force, and the brake pedal 41 enters a state of being biasedand swung to the initial position (“off”) by the return spring 42. Theslit 17 e is closed off once assembly of the brake pedal 41 is finished.

[Configurations of Steering-Post Cover and Panel Cover]

The steering wheel 11 is supported in a state of being able to changepositions in the vehicle-body longitudinal direction and thevehicle-body vertical direction. As illustrated in FIG. 8 , asteering-post cover 50 is inserted into a through hole 52 of a panelcover 51 supported on the traveling vehicle body 3. When the steeringwheel 11 changes positions in the vehicle-body longitudinal direction,the steering-post cover 50 follows the steering wheel 11 and swings inthe vehicle-body longitudinal direction relative to the panel cover 51.A bellows-shaped expandable cover 53 is connected across a proximal-sidelower portion of the steering-post cover 50 and a lower portion 51 a ofthe panel cover 51. The expandable cover 53 expands and contractsaccording to the swinging of the steering-post cover 50 but, regardlessof the swinging of the steering-post cover 50, places a gap between thesteering-post cover 50 and the lower portion 51 a of the panel cover 51in a closed state. Between a part opposing a distal-side wall portion ofthe steering-post cover 50 of the panel cover 51 and the distal-sidewall portion of the steering-post cover 50, a gap that allows thesteering-post cover 50 to swing is provided. However, above the gap andon the distal-side wall portion of the steering-post cover 50, a bulgingportion that bulges toward a cover outer side and makes the gapdifficult to see from above is provided. In the panel cover 51, a faceportion 51 b corresponding to a side portion of the steering-post cover50 is raised to the proximal side. Even if the steering-post cover 50swings, the face portion 51 b makes it difficult to see the gap betweenthe steering-post cover 50 and the panel cover 51 on a horizontal sideof the steering-post cover 50.

Other Embodiments

(1) FIG. 9 is a back view of a panel cover 55 provided with anotherexample of one or more embodiments. FIG. 10 is a perspective view of asteering post cover 56 provided with another example of one or moreembodiments. In the panel cover 55 provided with another example, belowa through hole 57 into which the steering-post cover 56 is inserted, anopening 58 and a proximal wall 59 extending upward from a lower edgeportion of the opening 58 are provided. In the steering-post cover 56,on a proximal-side lower portion, a proximal extended portion 61 thatextends lower than a lower end 60 a of a horizontal wall portion 60 isprovided, and on a distal-side lower portion, a distal extended portion62 that extends lower than the lower end 60 a of the horizontal wallportion 60 is provided. The proximal wall 59, the proximal extendedportion 61, and the distal extended portion 62 serve as hiding wallsthat make it difficult to see into an area below the panel cover 55 viaa gap arising between the steering-post cover 56 and the panel cover 55on a proximal side and horizontal side of the steering-post cover 56.

(2) In the embodiments described above, a configuration in which thesupport column 31 extends from the flywheel housing 6 is given, but theconfiguration is not limited thereto, and the support column 31 mayextend from any portion of the vehicle body frame 4.

(3) In the embodiments described above, an example in which the positionadjustment tool 35 is provided is given, but the position adjustmenttool 35 need not be provided.

(4) In the embodiments described above, an example in which the lowersupport portion 33 and the second position adjustment tool 37 isprovided is given, but the lower support portion 33 need not beprovided. Also, the lower support portion 33 may be provided, and thesecond position adjustment tool 37 need not be provided.

(5) In the embodiments described above, an example in which the lowersupport portion 33 is provided on the washer portion 34 is given, butthe lower support portion 33 need not be provided on the washer portion34 and may be provided directly on the support column 31.

INDUSTRIAL APPLICABILITY

One or more embodiments of the present invention can be applied to atractor provided with an engine bonnet forming an engine compartment.

Although the disclosure has been described with respect to only alimited number of embodiments, those skilled in the art, having benefitof this disclosure, will appreciate that various other embodiments maybe devised without departing from the scope of the present invention.Accordingly, the scope of the invention should be limited only by theattached claims.

1. A tractor comprising: a vehicle body; an engine bonnet that forms anengine compartment; an engine that is disposed in the enginecompartment; a first exhaust-gas cleaning device that is disposed in theengine compartment and purifies exhaust gas discharged from the engine,the first exhaust-gas cleaning device being disposed above the enginesuch that a long side of the first exhaust-gas cleaning device issubstantially parallel to a vehicle-body lateral width direction; asecond exhaust-gas cleaning device that is disposed in the enginecompartment and purifies the exhaust gas, the second exhaust-gascleaning device being disposed behind the engine such that a long sideof the second exhaust-gas cleaning device is substantially parallel tothe vehicle-body lateral width direction; a vehicle body frame; and asupporting tool that: is supported by the vehicle body frame, supportsthe first exhaust-gas cleaning device and the second exhaust-gascleaning device, and a support column that extends upward from thevehicle body frame along a front portion of the second exhaust-gascleaning device while supporting the front portion, and a support armthat extends forward from an upper portion of the support column along alower portion of the first exhaust-gas cleaning device while supportingthe lower portion.
 2. The tractor according to claim 1, wherein thevehicle body frame comprises: a flywheel housing that extends backwardfrom a back portion of the engine and positioned below the secondexhaust-gas cleaning device, and the support column extends upward fromthe flywheel housing.
 3. The tractor according to claim 2, furthercomprising: a first position adjustment tool that adjusts a supportposition of the second exhaust-gas cleaning device, on the supportcolumn, in a vehicle-body vertical direction, a vehicle-bodylongitudinal direction, and a vehicle-body lateral width direction. 4.The tractor according to claim 1, further comprising: a lower supportportion that is supported below the support column and supports a lowerportion of the second exhaust-gas cleaning device.
 5. The tractoraccording to claim 4, further comprising: a second position adjustmenttool that adjusts a support position of the second exhaust-gas cleaningdevice, on the lower support portion in a vehicle-body verticaldirection, a vehicle-body longitudinal direction, and a vehicle-bodylateral width direction.
 6. The tractor according to claim 4, whereinthe support column comprises: a washer portion that is disposed at alower portion of the support column and is connected to the vehicle bodyframe to make the support column supported by the vehicle body frame,and the lower support portion constitutes a part of the washer portion.